Lawn watering is generally anything but a precise process. Many people water when the lawn looks dry or when they think of it. Alternatively, a watering system may be on a timer whereby the lawn is watered at timed intervals, irrespective of whether or not it needs watering.
Apparatus to determine moisture content in various substances have been available in different forms and with varying degrees of success. However, a simple, inexpensive and practical system for sensing moisture percentage in media such as earth, in order to provide indications which may be adapted for controlling a lawn watering system, has not previously been available.